1. Field of the Invention
This invention relates in general to automated arc welding systems, and more particularly to automated arc welding systems wherein an oscillating movement is imparted to the welding electrode during the welding operation.
2. Description of the Prior Art
Welding systems heretofore provided control of penetration, fusion, and other welding parameters by oscillating the welding torch or electrode head. In some cases, the speed of oscillations is varied, and/or the welding current is increased and decreased, for providing an optimum welding bead. In some instances, the prior art welding head oscillating mechanism is adjustable to vary the amplitude of oscillation during the welding operation.
The U.S. Pat. to Valentine No. 3,571,557 discloses a welding torch guided by a linearly movable slide. A rocking link with a slotted body is pivoted to the slide and a slotted portion of the link is engaged by a movable fulcrum nut. The fulcrum nut is threaded on an adjustment shaft which may be manually turned by a handwheel, thus moving the fulcrum nut along the rocking link to change the amplitude of oscillation of the slide, and of the welding torch attached thereto. The device disclosed in the patent to Valentine is not remotely operable, and due to its proximity to the weld area is not considered to be, as a practical arrangement, adjustable in operation when welding currents in the order of 1,000 amperes are employed, as in the present instance.
In the U.S. Pat. to Hirano, No. 3,845,271, there is disclosed an oscillating type automatic arc welding apparatus in which the drive motor shaft axis is perpendicular to the reciprocating connecting rod. The patent to Hirano teaches adjusting the stroke of the connecting rod by altering the discs between the central axis of the drive motor shaft and the main shaft. The main shaft has an eccentric movement.
The U.S. Pat. to Arikawa et al. No. 3,832,522 discloses a welding process and apparatus in which a rotary disc imparts a reciprocating motion to the torch tip. A timing motor controls the rotation angle of the rotary disc to regulate the amplitude of the oscillating movement of the torch tip. The U.S. Pat. to Cape, No. 3,619,552 discloses an oscillating welding electrode for an automatic welding machine in which adjustable abutment surfaces on opposite sides of a headed screw limit the amplitude of the oscillatory movement of the welding gun.
In the prior art patents, it appears that the welding head moves over an arcuate path and thus, the weld bead assumes an arcuate configuration. A welding head travelling over an arcuate path requires higher welding currents than a welding head travelling over a rectilinear path.
Other U.S. patents of interest are:
No. 3,621,183 PA1 No. 3,681,564
Apparatus of the general description of the present invention has been manufactured and sold by Arcair of Lancaster, Ohio.